2011 / Number 15
TRI NEWSLETTER Dear friends and colleagues,
Recently published literature I
Tinnitus Research has evolved remarkably in the last years. Year after year there are more publications dealing with tinnitus, and - probably even more important- the methodological and scientific quality of research improved enormously. It is impressive how many tinnitus studies appeared in the last three months in most prestigious journals such as Journal of Neuroscience, Neuron or Nature. Thus tinnitus as a research topic reached the best labs and the brightest minds, a development which is also reflected by a tinnitus symposium at the last year‘s Meeting of the Society for Neuroscience. This means that tinnitus has finally reached the stage where it has become a scientifically acceptable and intellectually interesting matter to study. This development is of fundamental importance for all patients suffering from tinnitus, since the better the underlying mechanisms are understood, the higher the chances for more effective treatments in the near future. In addition, from a mere statistical point of view this change is also important. Many more young bright researchers will start investigating this enigmatic symptom, increasing the chances that someone will be bright or lucky enough to make a real breakthrough. Once a critical mass of highly motivated young people start investigating the problem, a final solution is more likely. Although initially probably not every single person suffering from tinnitus will find a cure, an increasing number of patients will find relief over time. It is one of the main priorities of TRI to communicate these latest research results. Thus we decided to add an additional section to the newsletter, where we inform about recent research highlights. You will find this new section on the following page.
VII Brain Stimulation
VIII Behavioral Therapy
The amount of new high quality research is also the motivation for the motto of this year‘s TRI Meeting: „The Neuroscience of Tinnitus“. We invite all of you to join us in Buffalo in August to share the most recent research results and to discuss future research directions and implications for clinical management. As usual you can find more detailed information regarding the meeting on the TRI website www.tinnitusresearch.org Let us embrace this wonderful scientific momentum and work even harder and together, basic scientists and clinicians alike, to find a solution.
XIV Case Reports
Ana Belén Elgoyhen
Dirk de Ridder
DISCLAIMER The Tinnitus Research Initiative, its representatives and employees (TRI) make no representations or warranties with respect to this newsletter. This newsletter provides INFORMATION – and does not provide medical advice. All the information and contents provided in this newsletter are provided for educational and informational purposes only. The scientific and medical information contained in this newsletter is not intended to be a substitute for professional medical advice, diagnosis, or treatment. You should always seek the advice of qualified healthcare professionals who are familiar with your individual medical needs. TRI, its representatives and employees, to the fullest extent permitted by law, disclaim all warranties, either express or implied, statutory or otherwise, including but not limited to all implied warranties of merchantability, non- infringement of third party rights, and fitness for a particular purpose. Specifically, TRI makes no representations or warranties as to the reliability, accuracy, timeliness or completeness of the information and content of this newsletter. Image Source: www.photocase.de
HIGHLIGHTS Kaltenbach JA. Tinnitus: Models and mechanisms. Hear Res. 2010 [Epub ahead of print]. A comprehensive review covering the cellular and molecular mechanisms underlying tinnitus generation. Noreña AJ. An integrative model of tinnitus based on a central gain controlling neural sensitivity. Neurosci Biobehav Rev. 2010 Nov 19. [Epub ahead of print]. Integrating findings from basic and clinical research Arnaud Norena proposes a testable model for tinnitus generation. Roberts LE, Eggermont JJ, Caspary DM, Shore SE, Melcher JR, Kaltenbach JA. Ringing ears: the neuroscience of tinnitus. J Neurosci. 2010;30(45):14972-9. Reviewing the neuroscience of tinnitus the latest findings from various methods are presented. Leaver AM, Renier L, Chevillet MA, Morgan S, Kim HJ, Rauschecker JP. Dysregulation of limbic and auditory networks in tinnitus. Neuron. 2011;69(1):33-43. This imaging study highlights the importance of audio-limbic interactions in the pathophysiology of tinnitus. Ortmann M, Müller N, Schlee W, Weisz N. Rapid increases of gamma power in the auditory cortex following noise trauma in humans. Eur J Neurosci. 2010 Dec 29 [Epub ahead of print]. Rock musicians after band practice were investigated with MEG to identify the neuronal correlates of transient tinnitus following noise trauma. Gu JW, Halpin CF, Nam EC, Levine RA, Melcher JR. Tinnitus, diminished sound-level tolerance, and elevated auditory activity in humans with clinically normal hearing sensitivity. J Neurophysiol. 2010;104(6):3361-70. This fMRI study differentiates tinnitus- and hyperacousis related abnomalities of sound evoked auditory pathway activity. Muehlmeier G, Biesinger E, Maier H. Safety of Intratympanic Injection of AM-101 in Patients with Acute Inner Ear Tinnitus. Audiol Neurootol. 2011;16(6):388-397. First results from a pilot trial investigating topical administration of a NMDA receptor antagonist for the treatment of acute tinnitus. Suckfuell M, Althaus M, Ellers-Lenz B, Gebauer A, Goertelmeyer R, Jastreboff PJ, Moebius HJ, Rosenberg T, Russ H, Wirth Y, Krueger H. A randomized, double-blind, placebo-controlled clinical trial to evaluate the efficacy and safety of neramexane in patients with moderate to severe subjective tinnitus. BMC Ear Nose Throat Disord. 2011;11(1):1. Neramexane, an antagonist at α9α10 cholinergic nicotinic receptors and N-methyl-D-aspartate receptors shows efficacy in the treatment of tinnitus in this phase II study. Bauer CA, Brozoski TJ. Effect of Tinnitus Retraining Therapy on the Loudness and Annoyance of Tinnitus: A Controlled Trial. Ear Hear. 2010 Sep 30. [Epub ahead of print]. This controlled clinical demonstrated that both TRT and general counseling without additional sound therapy are effective in reducing the annoyance and impact of tinnitus. Hesser H, Weise C, Westin VZ, Andersson G. A systematic review and meta-analysis of randomized controlled trials of cognitive-behavioral therapy for tinnitus distress. Clin Psychol Rev. 2010 Dec 23. [Epub ahead of print]. This meta-analysis concludes that CBT is an effective treatment of tinnitus distress. However there are only few large-scale, well-controlled trials. Hobson J, Chisholm E, El Refaie A. Sound therapy (masking) in the management of tinnitus in adults. Cochrane Database Syst Rev. 2010 Dec 8;12:CD006371. This Cochrane meta-analysis failed to show strong evidence of the efficacy of sound therapy in tinnitus. back to content
De Ridder D, Vanneste S, Kovacs S, Sunaert S, Menovsky T, van de Heyning P, Møller A. Transcranial magnetic stimulation and extradural electrodes implanted on secondary auditory cortex for tinnitus suppression. J Neurosurg. 2011 Jan 14. [Epub ahead of print]. Here clinical results from transcranial magnetic and intracranial electrical stimulation of the auditory cortex in a large series of 43 patients are reported. Zhang J, Zhang Y, Zhang X. Auditory Cortex Electrical Stimulation Suppresses Tinnitus in Rats. J Assoc Res Otolaryngol. 2010 Nov 6. [Epub ahead of print]. This animal study demonstrates that auditory cortex electrical stimulation suppresses behavioural evidence of tinnitus in rats. Engineer ND, Riley JR, Seale JD, Vrana WA, Shetake JA, Sudanagunta SP, Borland MS, Kilgard MP. Reversing pathological neural activity using targeted plasticity. Nature. 2011 470(7332):101-104. By combining specific auditory stimulation with vagal nerve stimulation these researchers were able to reverse both behavioural evidence and neuronal correlates of tinnitus in rats.
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Fifth International TRI Tinnitus Conference The Neuroscience of Tinnitus Holiday Inn Grand Island Resort and Conference Center Grand Island, New York, U.S.A. August 19 - 21, 2011 Organized by: The Center for Hearing and Deafness at the State University of New York at Buffalo and the Tinnitus Research Initiative, University of Regensburg, Germany Conference Topics: Central Mechanism of Tinnitus Pharmacological Targets for Tinnitus Peripheral Mechanism of Tinnitus Role of Non-Auditory Brain Areas in Tinnitus Functional Imaging of Tinnitus
Role of Non-Auditory Brain Areas in Tinnitus Repeated Transcranial Magnetic Stimulation Therapy Tinnitus Sound Therapies Electrical Stimulation Therapies Somatic Tinnitus and Novel Therapies
Sponsorships: Office of Naval Research Med-El Corporation Widex Conference and Registration Administrator: Carol M. Altman, Center of Hearing and Deafmess at the State University of New York at Buffalo, USA, phone (716) 829-5291, Fax (716) 829-2980, e-mail: [email protected]
Conference Contact Germany: Susanne Staudinger, Sylvia Dorner-Mitschke, TRI Office, University of Regensburg, Germany, phone +49 941 941 2096, Fax +49 941 941 2025, e-mail: [email protected]
The Sixth International Tinnitus Conference
is expected to take place in June 2012 in Bruges, Belgium.
For more detailed information about the two conferences please look at www.tinnitusresearch.org back to content
Upcoming Meetings Meetings exclusively dedicated to Tinnitus are marked red March 2011
12th Asia-Oceania Otolaryngology Conference When: Where: Contact: phone: Fax: E-mail: Detailed Information:
March 1 – 4, 2011 Auckland, New Zealand The Conference Company PO Box 90-040, Auckland, New Zealand +64 9 360 1240 +64 9 360 1242 [email protected]
American Auditory Society Annual Meeting When: March 3 – 5, 2011 Where: Scottsdale, AZ, United States Detailed Information: http://www.amauditorysoc.org/annual-meeting/reginfo.htm
14. Jahrestagung der Deutschen Gesellschaft für Audiologie (DGA e.V.) When: March 10 – 13, 2011 Where: Jena, Germany Detailed Information: http://www.uzh.ch/orl/dga-ev/Flyer_DGA_Jena_2011.pdf
X International Tinnitus Seminar - ITS 2011 When: March 16 – 19, 2011 Where: Florianopolis, Santa Catarina, Brazil Detailed Information: http://www.its2011brazil.com.br
55. Jahrestagung der Deutschen Gesellschaft für Klinische Neurophysiologie und Funktionelle Bildgebung (DGKN) When: March 16 – 19, 2011 Where: Münster, Germany Detailed Information: http://www.congrex.de/dgkn2011
37. Jahrestagung der Deutschen Gesellschaft für Akustik DEGA (DAGA 2011) When: March 21 – 24, 2011 Where: Düsseldorf, Germany Detailed Information: http://www.dega-akustik.de/
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9th Göttingen Meeting of the German Neuroscience Society When: Where: Contact: Phone: Fax: E-Mail: Detailed Information:
March 23 – 27, 2011 Göttingen, Germany German Neuroscience Society (Neurowissenschaftliche Gesellschaft e.V. /NWG) MDC Robert-Rössle-Str. 10, 13125 Berlin +49 (0)30 9406 3336 +49 (0)30 9406 2813 [email protected]
Academy Research Conference - Current Trends in the Evaluation of Tinnitus (a day-long conference coinciding with the first day of AudiologyNOW! 2011) When: April 6, 2011 Where: Chicago, IL, United States Detailed Information: www.AcademyResearchConference.org
AudiologyNOW!® 2011 When: April 6 – 9, 2011 Where: Mc Cormick Place Convention Center Chicago, IL, United States Detailed Information: www.AudiologyNOW.org
International Conference on Theoretical & Computational Acoustics (ICTCA) 2011 When: Where: Contact: Phone: Fax: E-mail: Detailed Information:
April 25 – 28, 2011 Taipei, Taiwan Miss Pichun Wu Department of Engineering Science and Ocean Engineering, National Taiwan University +886-2-3366-5735 +886-2-3366-5781 [email protected]
161st Meeting of the Acoustical Society of America When: Where: E-Mail: Detailed Information:
May 23 – 27, 2011 Seattle, Washington [email protected]
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82. Jahresversammlung der Deutschen Gesellschaft für Hals-Nasen-OhrenHeilkunde, Kopf- und Hals-Chirurgie e.V. When: Where: Contact: Phone: Fax: E-Mail: Detailed Informaiton:
June 1 – 5, 2011 Freiburg, Germany Deutsche Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie, Hittorfstr. 7, 53129 Bonn +49 (0)2 28/23 17 70 +49 (0)2 28/23 93 85 [email protected]
10th EFAS Congress When: Where: E-Mail: Detailed Information:
June 22 – 25, 2011 Warsaw, Poland [email protected]
Human Brain Mapping Annual Meeting When: June 26 – 30, 2011 Where: Quebec City, Canada Detailed Information: www.humanbrainmapping.org
XXII IERASG Biennal Symposium When: June 26 – 30, 2011 Where: Moscow, Russia Detailed Information: http://www.ierasg2011.ru/
1st Congress of the Confederation of the European ORL-HNS When: July 2 – 4, 2011 Where: Barcelona, Spain Detailed Information: http://www.ceorlhnsbarcelona2011.org/
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5th International TRI Tinnitus Conference. The Neuroscience of Tinnitus. When: Where: E-Mail: Detailed Information:
August, 19 – 21, 2011 Buffalo, NY, USA [email protected]
American Academy of Otolaryngology, Head and Neck Surgery Annual Meeting When: September 11 – 14, 2011 Where: San Francisco, CA, USA Detailed Information: http://www.entnet.org
28. Politzer Society Meeting When: Where: Contact: Phone: Fax: E-Mail: Detailed Information:
September 29 – October 1, 2011 Zappeion Exhibition Hall, Athens, Greece GOLDAIR Congress, 15 Panepistimiou Avenue, 10564 Athens, Greece +30 210 3274570 +30 210 3311021 [email protected]
and/or [email protected]
8th Meeting of the British Society of Neuro-Otology When: Where: Contact: Phone: Fax: E-Mail: Detailed Information:
October 14, 2011 National Hospital for Neurology and Neurosurgery, Queen Square, London Miss J. Mills, Neuro-Otology Group, Imperial College London, Charing Cross Hospital Fulham Palace Road London W6 8RF +44 (0)208 846 7285 +44 (0)208 846 7577 [email protected]
56th International Congress of Hearing Aid Acousticians When: October 19 – 21, 2011 Where: CongressCenter Nürnberg, CCN East, Germany Detailed Information: http://www.euha.org
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Asia Pacific symposium on Cochlear Implant and Related Science When: October 26 – 28, 2011 Where: Korea Detailed Information: http://knuh.knu.ac.kr
162nd Meeting of the Acoustical Society of America When: Where: E-Mail: Detailed Information:
October 31 – November 4, 2011 San Diego, California, United States [email protected]
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Recently published literature (articles of authors who are funded by TRI are marked in blue) I Epidemiology Occupational exposure to noise and the prevalence of hearing loss in a Belgian military population: A cross-sectional study. Noise Health. 2011 Jan-Feb;13(50):64-70. Coll E A, Legrand C, Govaerts B, Veken PV, De Boodt F, Degrave E. Unit of Epidemiology and Biostatistics, Staff Department Well Being, Bruynstreet 1, 1120 Brussels, Belgium. The armed forces are highly exposed to occupational noise. The aim of this study was to evaluate the prevalence and noise exposures associated with the severity of hearing loss (HL) in a Belgian military population. A cross-sectional study was carried out at the Centre for Medical Expertise (CME) and in four Units of Occupational Medicine (UOM). Hearing thresholds were determined by audiometry. The examination included a questionnaire on hearing-related medical history, and noise exposure in military and leisure time activity. A multinomial logistic regression model was used to assess the association of the severity of HL with tinnitus, with the military occupation, and with noise exposures. Of the 2055 subjects aged 18-55 years, 661 (32.2%) had a slight HL (25-40 dB), 280 (13.6%) had a moderate HL (45-60 dB) and 206 (10.0%) had a severe HL (>60 dB) of 4 and 6 kHz for both ears. The prevalence of slight, moderate and severe HL increased significantly with age and was higher for subjects from Paracommando and infantry units. Fighting in Built-Up Area (FIBUA) training, shooting with large caliber weapons, and participation in military exercises were the best determinants of HL in this population. These results suggest that subjects from infantry and Paracommando units run the highest risk of HL because they are exposed to very loud noises in their professional life, like large caliber shooting and FIBUA training. Hearing loss among classical-orchestra musicians. Noise Health. 2011 Jan-Feb;13(50):45-50. Toppila E, Koskinen H, Pyykko I. Finnish Institute of Occupational Health, Finland. This study intended to evaluate classical musicians‘ risk of hearing loss. We studied 63 musicians from four Helsinki classical orchestras. We measured their hearing loss with an audiometer, found their prior amount of exposure to sound and some individual susceptibility factors with a questionnaire, measured their present sound exposure with dosimeters, and tested their blood pressure and cholesterol levels, then compared their hearing loss to ISO 1999-1990‘s predictions. The musicians‘ hearing loss distribution corresponded to that of the general population, but highly exposed musicians had greater hearing loss at frequencies over 3 kHz than less-exposed ones. Their individual susceptibly factors were low. Music deteriorates hearing, but by less than what ISO 1999-1990 predicted. The low number of individual susceptibility factors explained the difference, but only reduced hearing loss and not the prevalence of tinnitus.
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Tinnitus in the elderly: Profile, correlates, and impact in the Nigerian Study of Ageing. Otolaryngol Head Neck Surg. 2010 Oct;143(4):510-5. Lasisi AO, Abiona T, Gureje O. Department of Otorhinolaryngology, College of Medicine, University of Ibadan, Ibadan, Oyo State, Nigeria. [email protected]
OBJECTIVE: To determine the prevalence and correlates of tinnitus among community elderly and its impact on their quality of life. STUDY DESIGN: Longitudinal cohort. SETTING: Yoruba-speaking communities in Nigeria. SUBJECTS AND METHODS: Face-to-face interviews of 1302 subjects 65 years or older selected by the use of a multistage stratified sampling of households. Subjects were assessed for subjective tinnitus, chronic health conditions, functional impairment, and quality of life by use of the brief version of the World Health Organization quality of life instrument. RESULTS: Tinnitus was reported in 184 (110 female and 74 male subjects), giving a prevalence of 14.1 percent (SE = 0.49). Gender, age, economic status, educational level, residence, smoking, and alcohol consumption were not significantly associated with tinnitus. Univariate analysis revealed a history of recurrent otitis media (odds ratio [OR] = 4.5, 95% confidence interval [95% CI] 3.1-6.6, P = 0.01), head injury (OR 3.4, 95% CI 2.1-5.6, P = 0.01), rhinosinusitis (OR 2.4, 95% CI 1.5-4.0, P = 0.01), dizziness (OR 2.1, 95% CI 1.4-3.1, P = 0.01), and hypertension (OR 1.7, 95% CI 1.0-2.7, P = 0.05) as significant correlates. However, in multivariate analysis, only a history of otitis media and of head injury remained significant. Compared with those without, persons with tinnitus had a more negative perception of their overall health and a poorer quality of life as well as twofold likelihood to experience impairment in both activities of daily living and instrumental activities of daily living. CONCLUSION: Tinnitus is common among elderly Nigerians and is associated with treatable health conditions, such as otitis media, rhinosinusitis, head injury, and hypertension. Its association with functional impairment and reduced quality of life highlights the need for inclusion in any comprehensive health care for the elderly. Occupational Hearing Loss in Korea. J Korean Med Sci. 2010 Dec;25(Suppl):S62-S69. Epub 2010 Dec 15. Kim KS. Occupational Safety and Health Research Institute, Korea Occupational Safety and Health Agency, Incheon, Korea. In this article, current status of noise exposure in workplaces, trend of workers with noise-induced hearing loss (NIHL), and prevalence of NIHL in workers by industry and job category in Korea were reviewed. In addition, trends of research on the audiological effects such as hearing loss from noise and occupational hearing loss from non-noise in Korea were addressed through reports in industrial audiology. Though noise exposure level has improved, noise still shows the highest rate of cases exceeding exposure limit among workplace hazards. NIHL is the most common occupational disease except work-related disease such as musculoskeletal disorders and cerebrovascular diseases, and NIHL prevalence is thought to be much higher than reported in official publications. Noise affecting hearing comes from various sources such as workplaces, military settings, areas with exposure to high noise, and specific noise sources. There is also occupational hearing loss by non-noise including chemicals such as organic solvents and heavy metals, barotrauma, and trauma due to welding spark. Noise affects daily life through audiological effects such as hearing loss and tinnitus, non-audiological physical effects (e.g., cardiovascular), and psychosocial and behavioral effects. Development of systematic and comprehensive hearing conservation programs for lowering the noise level in workplaces and preventing the NIHL, and preparation of technological, administrative system for its settlement at workplace are urgently needed. back to content
High frequency hearing sensitivity in adolescent females of a lower socioeconomic status over a period of 24 years (1985-2008). J Adolesc Health. 2011 Feb;48(2):203-8. Epub 2010 Sep 1. Berg AL, Serpanos YC. Dept of Biology and Health Sciences, Communication Sciences and Disorders Program, Dyson College of Arts and Sciences, Pace University, New York; Depts of Otolaryngology/Head and Neck Surgery and Pediatrics, College of Physicians and Surgeons, Columbia University, New York. PURPOSE: To examine annually over a period of 24 years, the high frequency hearing sensitivity in different groups of urban female adolescents with a low socioeconomic status (SES) and residential foster care. METHODS: Hearing screening (15 decibel [dB] hearing level ranging from 1,000 to 8,000 Hertz [Hz]) and threshold (>15 dB hearing level) records were obtained from 8,710 female adolescents (mean age, 15.8 years [range, 12-20 years]), predominantly Hispanic and African American from households with a low SES. Data related to the use of personal listening devices (PLDs), daily hours of usage, occurrence of tinnitus, and hearing thresholds between 1,000 and 8,000 Hz over an 8-year period (2001-2008) were obtained from the adolescents. RESULTS: High frequency hearing loss (HFHL) doubled over the 24-year period from 10.1% in 1985 to 19.2% in 2008. In comparison with the general adolescent population, this group of female adolescents presented with a higher percentage of bilateral mild or greater degrees of HFHL at two or more frequencies including 3,000, 4,000, and 6,000 Hz. Use of PLDs increased four-fold, from 18.3% (n = 68) in 2001 to 76.4% (n = 227) in 2008. Of the total number reporting tinnitus (n = 286), 99.7% (n = 285) also reported regular PLD use. A significant relationship was found between PLD use and reported tinnitus and HFHL irrespective of time of use of PLD. CONCLUSIONS: Increased incidence of HFHL, reported tinnitus, PLD use, and hours of daily use in at-risk female adolescents of a low SES was found. A frequency interval of 3,000-6,000 Hz should be included in hearing screening protocols to identify potentially disabling hearing loss. Hearing conservation strategies need to be developed and/or modified that target and reach at-risk children and adolescents. Copyright © 2011 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved Prevalence of otolaryngologic diseases in South Korea: data from the Korea national health and nutrition examination survey 2008. Clin Exp Otorhinolaryngol. 2010 Dec;3(4):183-93. Epub 2010 Dec 22. Cho YS, Choi SH, Park KH, Park HJ, Kim JW, Moon IJ, Rhee CS, Kim KS, Sun DI, Lee SH, Koo JW, Koh YW, Lee KH, Lee SW, Oh KW, Pyo EY, Lee A, Kim YT, Lee CH. Dept of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. OBJECTIVES: The aims of this study were to evaluate the prevalence of otolaryngologic diseases in Korea. METHODS: We obtained data from the 2008 Korea National Health and Nutrition Examination Surveys (KNHANES), which were cross-sectional surveys of the civilian, non-institutionalized population of South Korea (n=4,930). A field survey team that included an otolaryngologist, nurses, and interviewers moved with a mobile examination unit and performed otolaryngologic interviews and physical examinations. RESULTS: The prevalence of subjective hearing loss, tinnitus, preauricular fistua, tympanic membrane perforation, and cholesteatoma were 11.97%, 20.27%, 2.08%, 1.60%, and 1.18%, respectively. Dizziness and vestibular dysfunction were common among Korean adults, since 23.33% of the participants reported symptoms of dizziness or imbalance, and the prevalence of vestibular dysfunction was 3.86%. The prevalence of nasal diseases was relatively high, as the prevalence of allergic rhinitis, chronic rhinosinusitis, and a deviated nasal septum were 28.01%, 7.12%, and 42.94%, respectively. Subjective dysphonia was found in 6.60% of the participants, and the prevalence of subjective dysphonia increased with age. CONCLUSION: This is the first nation-wide epidemiologic study to assess the prevalence of otolaryngologic diseases by both the Korean Otolaryngologic Society and the Ministry of Health and Welfare. Considering the high prevalence of otolaryngologic diseases in Korea, the results call for additional studies to better prevent and manage otolaryngologic diseases. back to content
II Pathophysiology Activation of Serotonergic Neurons During Salicylate-Induced Tinnitus. Otol Neurotol. 2010 Dec 29. [Epub ahead of print] Caperton KK, Thompson AM. Dept of Otorhinolaryngology, University of Oklahoma Health Sciences Center, Oklahoma City, Ok, U.S.A. HYPOTHESIS: Serotonergic neurons are activated during salicylate-induced tinnitus and modulate the cochlea during tinnitus. BACKGROUND: During salicylate-induced tinnitus in the gerbil, neurons in the dorsal raphe nucleus were activated. Because approximately half of the neurons in this region are serotonergic, this indicates that serotonin (5-HT) might play a role in the mechanisms of central tinnitus. The goal of this study was to determine if serotonergic neurons are activated during salicylate-induced tinnitus. Furthermore, to determine if the same neurons might modulate the cochlea during tinnitus, neuroanatomic tract-tracing with 5-HT immunohistochemistry was used to determine if serotonergic neurons project to the gerbil cochlea. METHODS: A randomized, prospective study was performed. Six gerbils were injected with salicylate (saline for controls). Four hours later, the gerbils were euthanized and perfused, and their brains were collected for immunohistochemical labeling of 5-HT and c-fos. For the tract-tracing, FluoroGold was injected into the cochleae of 3 gerbils. The gerbils were euthanized and perfused 4 to 11 days later, and the brains immunohistochemically were processed for 5-HT. RESULTS: More serotonergic neurons expressed c-fos in the salicylate-injected animals compared with the controls. The increase was significant for 3 of the 8 major serotonergic cell groups including B7, B9, and the caudal linear nucleus. Despite robust labeling of olivocochlear and vestibular efferents with FluoroGold, 5-HT-labeled neurons containing FluoroGold were lacking. CONCLUSION: Salicylateinduced tinnitus activates serotonergic neurons in rostral cell groups. Activation of these neurons is not likely to influence cochlear function directly but is likely to influence a number of auditory and nonauditory regions known to be involved with tinnitus. Synaptic plasticity in inhibitory neurons of the auditory brainstem. Neuropharmacology. 2010 Dec 23. [Epub ahead of print] Bender KJ, Trussell LO. Oregon Hearing Research Center and Vollum Institute, Oregon Health and Science University, 3181 S.W. Sam Jackson Park Road, L335A, Portland, OR 97239, USA. There is a growing appreciation of synaptic plasticity in the early levels of auditory processing, and particularly of its role in inhibitory circuits. Synaptic strength in auditory brainstem and midbrain is sensitive to standard protocols for induction of long-term depression, potentiation, and spike-timingdependent plasticity. Differential forms of plasticity are operative at synapses onto inhibitory versus excitatory neurons within a circuit, and together these could serve to tune circuits involved in sound localization or multisensory integration. Such activity-dependent control of synaptic function in inhibitory neurons may also be expressed after hearing loss and could underlie persistent neuronal activity in patients with tinnitus.
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Evidence of key tinnitus-related brain regions documented by a unique combination of manganese-enhanced MRI and acoustic startle reflex testing. PLoS One. 2010 Dec 15;5(12):e14260. Holt AG, Bissig D, Mirza N, Rajah G, Berkowitz B. Dept of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA. Animal models continue to improve our understanding of tinnitus pathogenesis and aid in development of new treatments. However, there are no diagnostic biomarkers for tinnitus-related pathophysiology for use in awake, freely moving animals. To address this disparity, two complementary methods were combined to examine reliable tinnitus models (rats repeatedly administered salicylate or exposed to a single noise event): inhibition of acoustic startle and manganese-enhanced MRI. Salicylate-induced tinnitus resulted in wide spread supernormal manganese uptake compared to noise-induced tinnitus. Neither model demonstrated significant differences in the auditory cortex. Only in the dorsal cortex of the inferior colliculus (DCIC) did both models exhibit supernormal uptake. Therefore, abnormal membrane depolarization in the DCIC appears to be important in tinnitus-mediated activity. Our results provide the foundation for future studies correlating the severity and longevity of tinnitus with hearing loss and neuronal activity in specific brain regions and tools for evaluating treatment efficacy across paradigms. Cuneate and spinal trigeminal nucleus projections to the cochlear nucleus are differentially associated with vesicular glutamate transporter-2. Neuroscience. 2010 Dec 15. [Epub ahead of print] Zeng C, Shroff H, Shore SE. Dept of Otolaryngology, Kresge Hearing Research Institute, University of Michigan, Ann Arbor, MI 48109, USA. There are distinct distributions and associations with vesicular glutamate transporters (VGLUTs) for auditory nerve and specific somatosensory projections in the cochlear nucleus (CN). Auditory nerve fibers project primarily to the magnocellular areas of the ventral cochlear nucleus and deepest layer of the dorsal cochlear nucleus and predominantly colabel with VGLUT1; whereas the spinal trigeminal nucleus (Sp5) projections terminate primarily in the granule cell domains (GCD) of CN and predominantly colabel with VGLUT2. Here, we demonstrate that the terminals of another somatosensory pathway, originating in the cuneate nucleus (Cu), also colabel with VGLUT2. Cu projections in cochlear nucleus exhibited a bilateral distribution pattern with ipsilateral dominance, with 30% of these classified as putative mossy fibers (MFs) and 70% as small boutons (SBs). Cu anterograde endings had a more prominent distribution in the GCD than Sp5, with a higher percentage of MF terminals throughout the CN and higher MF/SB ratio in GCD. 56% of Cu endings and only 25% of Sp5 endings colabeled with VGLUT2. In both cases these were mostly MFs with only 43% of Cu SBs and 18% of Sp5 SBs colabeled with VGLUT2. The few Cu and Sp5 terminals that colabeled with VGLUT1 (11% vs. 1%), were evenly distributed between MFs and SBs. The high number of VGLUT2-positive Cu MFs predominantly located in the GCD, may reflect a faster-acting pathway that activates primarily dorsal cochlear nucleus cells via granule cell axons. In contrast, the higher percentage of Sp5-labeled SB terminals and a greater number of projections outside the GCD suggest a slower-acting pathway that activates both dorsal and ventral cochlear nucleus principal cells. Both projections, with their associations to VGLUT2 likely play a role in the enhancement of VGLUT2 after unilateral deafness [Zeng C, Nannapaneni N, Zhou J, Hughes LF, Shore S (2009) J Neurosci 29:4210-4217] that may be associated with tinnitus.
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Hearing impairment after platinum-based chemotherapy in childhood. Pediatr Blood Cancer. 2010 Dec 15. [Epub ahead of print] Einar-Jon E, Trausti O, Asgeir H, Christian M, Thomas W, Måns M, Jon K, Hannes P. Faculty of Medicine, University of Iceland, Reykjavík, Iceland. BACKGROUND: Chemotherapy is used in the treatment of children and adolescents with malignant diseases. Some of the chemotherapeutic agents are highly toxic and may cause a number of side effects. The primary objective of this study was to evaluate the long-term effects on hearing in cancer survivors who had received platinum-based chemotherapy in childhood or adolescence. PROCEDURE: Medical records of 297 patients, who had received treatment for cancer at the Children‘s Hospital, Landspitali University Hospital in Iceland between 1981 and 2006, were retrospectively reviewed. Fifteen subjects fulfilled the eligibility criteria for the study and underwent an extended audiometric evaluation. RESULTS: The results showed that three of the subjects had a high frequency hearing loss. In one subject, we observed a hearing recovery just after the completion of chemotherapy, but the hearing deteriorated again some years later. Nine of the 15 subjects (60%) had tinnitus after the cancer treatment. An evaluation of subjective hearing disability and handicap (The Hearing Measurements Scale) revealed that some subjects had great difficulties with hearing in certain situations. The Hearing Measurement Scale showed that the pure-tone audiogram findings were only partly associated with the apparent hearing difficulties. CONCLUSION: Regular follow-up hearing examinations, which include both puretone audiogram investigations and subjective hearing disability assessments, should be performed during and after chemotherapy to identify subjects who require particular attention. This will ensure that hearing impaired individuals are provided with the most suitable listening devices, to promote good speech and social development. Pediatr Blood Cancer © 2010 Wiley-Liss, Inc. Tinnitus: Models and mechanisms. Hear Res. 2010 Dec 10. [Epub ahead of print] Kaltenbach JA. Department of Neurosciences, NE-63, Lerner Research Institute/Head and Neck Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44122, USA. Over the past decade, there has been a burgeoning of scientific interest in the neurobiological origins of tinnitus. During this period, numerous behavioral and physiological animal models have been developed which have yielded major clues concerning the likely neural correlates of acute and chronic forms of tinnitus and the processes leading to their induction. The data increasingly converge on the view that tinnitus is a systemic problem stemming from imbalances in the excitatory and inhibitory inputs to auditory neurons. Such changes occur at multiple levels of the auditory system and involve a combination of interacting phenomena that are triggered by loss of normal input from the inner ear. This loss sets in motion a number of plastic readjustments in the central auditory system and sometimes beyond the auditory system that culminate in the induction of aberrant states of activation that include hyperactivity, bursting discharges and increases in neural synchrony. This article will review was has been learned about the biological origins of these alterations, summarize where they occur and examine the cellular and molecular mechanisms that are most likely to underlie them.
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An integrative model of tinnitus based on a central gain controlling neural sensitivity. Neurosci Biobehav Rev. 2010 Nov 19. [Epub ahead of print] Noreña AJ. National Center of Scientific Research, Université de Provence, Integrative and Adaptive Neurobiology Laboratory, Université de Provence - Centre Saint-Charles Case B, 3, place Victor Hugo, 13333 Marseille Cedex, France. The purpose of the current review is to propose a model highlighting the putative connections between hearing loss and the phantom perception of tinnitus (tinnitus being accompanied by hearing loss in the majority, if not all, subjects). Sensory deprivation is followed by dramatic functional and structural changes in the auditory system. Notably, while cochlear injuries are accompanied by a reduced activity in the cochlear nerve, neural activity is increased at virtually all levels in the central auditory system. We suggest that this central hyperactivity could result from a central gain increase; the general purpose of this gain modulation being to adapt neural sensitivity to the reduced sensory inputs, preserving a stable mean firing and neural coding efficiency. However, maintaining neural homeostasis at all costs, in the event of an auditory system sensory deprivation, could be done at the price of amplifying „neural noise“ due to the overall increase of gain (or sensitivity), ultimately resulting in the generation of tinnitus. The clinical implications of this model are also presented. back to Highlights Ringing ears: the neuroscience of tinnitus. J Neurosci. 2010 Nov 10;30(45):14972-9. Roberts LE, Eggermont JJ, Caspary DM, Shore SE, Melcher JR, Kaltenbach JA. Department of Psychology, Neuroscience, and Behaviour, McMaster University, Hamilton, Ontario L8S 4K1, Canada. [email protected]
Tinnitus is a phantom sound (ringing of the ears) that affects quality of life for millions around the world and is associated in most cases with hearing impairment. This symposium will consider evidence that deafferentation of tonotopically organized central auditory structures leads to increased neuron spontaneous firing rates and neural synchrony in the hearing loss region. This region covers the frequency spectrum of tinnitus sounds, which are optimally suppressed following exposure to bandlimited noise covering the same frequencies. Cross-modal compensations in subcortical structures may contribute to tinnitus and its modulation by jaw-clenching and eye movements. Yet many older individuals with impaired hearing do not have tinnitus, possibly because age-related changes in inhibitory circuits are better preserved. A brain network involving limbic and other nonauditory regions is active in tinnitus and may be driven when spectrotemporal information conveyed by the damaged ear does not match that predicted by central auditory processing. back to Highlights
Childhood hearing and its relationship with tinnitus at thirty-two years of age. Ann Otol Rhinol Laryngol. 2010 Oct;119(10):672-6. Dawes PJ, Welch D. Dept of Otorhinolaryngology-Head and Neck Surgery, Dunedin Hospital, 201 Great King St, Dunedin, New Zealand. OBJECTIVES: Tinnitus is associated with hearing loss in adulthood, often resulting from noise or age, but it is not known whether children‘s hearing and/or middle ear health predispose them to tinnitus in adulthood. METHODS: The participants were members of the Dunedin Multidisciplinary Health and Development Study, born in Dunedin, New Zealand, between April 1972 and March 1973. The base sample consisted of 1,037 children. Otitis media was assessed at 5, 7, and 9 years of age; audiometry and tympanometry findings were recorded at 11 years of age, and a detailed description of the tympanic membrane was made at 15 years of age. At 32 years of age, 970 of the 1,015 living study members (96%) answered questions about tinnitus. 16 back to content
RESULTS: Children who had otitis media and a raised audiometric threshold went on to experience more tinnitus in adulthood than did those without middle ear disease or those who had otitis media without a raised threshold. In those who had recovered from otitis media, audiometric threshold elevation at lower and higher frequencies was associated with experiencing tinnitus in adulthood. Neither childhood otitis media alone nor elevated thresholds alone predicted adult tinnitus. CONCLUSIONS: Childhood otitis media with an associated hearing loss in the low and high frequencies was associated with a greater probability of experiencing tinnitus in adulthood. Salicylate induced neural changes in the primary auditory cortex of awake cats. Neuroscience. 2011 Jan 13;172:232-45. Epub 2010 Oct 31. Zhang X, Yang P, Cao Y, Qin L, Sato Y. Department of Physiology, China Medical University, Shenyang 110001, PR China; Department of Physiology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Yamanashi 409-3898, Japan. Systemic administration of salicylate at high doses can induce reversible tinnitus and hyperacusis in humans and animals. For this reason, a number of studies have investigated the salicylate-induced changes of neural activity in the auditory cortex (AC); however, most previous studies of the AC were conducted on brain slices or anesthetized animals, which cannot completely represent the actual conditions. Few efforts have been made to examine the neural activity of awake animals, and only recorded the local field potential (LFP) of the AC. In this study, we recorded neural spike activities from chronically implanted electrodes in the primary AC (A1) of awake cats, and investigated the changes of neural responses to pure-tone and click-train stimuli after systemic injection of 200 mg/kg salicylate. We found that sound-evoked spike activities were significantly increased from 1 h after salicylate administration, and the increase of neural responses lasted longer than 3 days with a peak at 12 h. Salicylate not only increased the amplitude of transient responses at the onset and offset of pure-tone stimuli, but also induced a sustained response during the prolonged stimulus period and a late response at ∼100 ms after stimulus offset. The significant enhancement of neural responses was observed over the entire tested frequency range (0.1-16 kHz) with a relative peak in the band of 3.2-9.6 kHz. The capability of exhibiting spikes synchronizing with successive clicks was also enhanced. All these effects were more apparent when the neurons were driven by high intensity sounds. Salicylate-administration also decreased the mean spontaneous rate in A1 units, and the decrease of spontaneous rate was larger in the units with a high initial spontaneous rate. Our data confirm that salicylate can modulate the neural activity at the cortical level and provide more information for understanding the mechanism of salicylate-induced tinnitus. Oxidative stress, redox homeostasis and cellular stress response in Ménière‘s disease: role of vitagenes. Neurochem Res. 2010 Dec;35(12):2208-17. Epub 2010 Nov 3. Calabrese V, Cornelius C, Maiolino L, Luca M, Chiaramonte R, Toscano MA, Serra A. Department of Chemistry, Faculty of Medicine, University of Catania, Catania, Italy. [email protected]
Ménière‘s disease (MD) is characterized by the triad of fluctuating hearing loss, episodic vertigo and tinnitus, and by endolymphatic hydrops found on post-mortem examination. Increasing evidence suggests that oxidative stress is involved in the development of endolymphatic hydrops and that cellular damage and apoptotic cell death might contribute to the sensorineural hearing loss found in later stages of MD. While excess reactive oxygen species (ROS) are toxic, regulated ROS, however, play an important role in cellular signaling. The ability of a cell to counteract stressful conditions, known as cellular stress response, requires the activation of pro-survival pathways and the production of molecules with anti-oxidant, anti-apoptotic or pro-apoptotic activities. Among the cellular pathways conferring protection against oxidative stress, a key role is played by vitagenes, which include heat shock proteins back to content
(Hsps) as well as the thioredoxin/thioredoxin reductase system. In this study we tested the hypothesis that in MD patients measurable increases in markers of cellular stress response and oxidative stress in peripheral blood are present. This study also explores the hypothesis that changes in the redox status of glutathione, the major endogenous antioxidant, associated with abnormal expression and activity of carbonic anhydrase can contribute to increase oxidative stress and to disruption of systemic redox homeostasis which can be associated to possible alterations on vulnerable neurons such as spiral ganglion neurons and consequent cellular degeneration. We therefore evaluated systemic oxidative stress and cellular stress response in patients suffering from Meniere’s disease (MD) and in agematched healthy subjects. Systemic oxidative stress was estimated by measuring protein oxidation, such as protein carbonyls (PC) and 4-hydroxynonenal (HNE) in lymphocytes of MD patients, as well as ultraweak luminescence (UCL) as end-stable products of lipid oxidation in MD plasma and lymphocytes, as compared to age-matched controls, whereas heat shock proteins Hsp70 and thioredoxin (Trx) expression were measured in lymphocytes to evaluate the systemic cellular stress response. Increased levels of PC (P < 0.01) and HNE (P < 0.05) have been found in lymphocytes from MD patients with respect to control group. This was paralleled by a significant induction of Hsp70, and a decreased expression of Trx (P < 0.01), whereas a significant decrease in both plasma and lymphocyte ratio reduced glutathione GSH) vs. oxidized glutathione (GSSG) (P < 0.05) were also observed. In conclusion, patients affected by MD are under condition of systemic oxidative stress and the induction of vitagenes Hsp70 is a maintained response in counteracting the intracellular pro-oxidant status generated by decreased content of GSH as well as expression of Trx. The search for novel and more potent inducers of vitagenes will facilitate the development of pharmacological strategies to increase the intrinsic capacity of vulnerable ganglion cells to maximize antidegenerative mechanisms, such as stress response and thus cytoprotection. Contralateral Suppression of Otoacoustic Emissions in Tinnitus Patients. Otol Neurotol. 2010 Oct 19. [Epub ahead of print] Geven LI, de Kleine E, Free RH, van Dijk P. Department of Otorhinolaryngology-Head and Neck Surgery, and †Faculty of Medical Sciences, School of Behavioral and Cognitive Neurosciences, University of Groningen, Groningen, The Netherlands. OBJECTIVE: To compare the functioning of the medial olivocochlear efferent system between tinnitus patients and control subjects. STUDY DESIGN: Prospective, nonrandomized controlled analysis of suppression of otoacoustic emissions with contralateral acoustic stimulation. SETTING: Tertiary referral center. PATIENTS: Initial analysis of 97 tinnitus patients and 44 control subjects with click-evoked otoacoustic emission measurement. If subjects had reproducible otoacoustic emissions at 80 dB SPL, suppression of otoacoustic emission with contralateral acoustic stimulation was measured with a 65-dB click stimulus. This resulted in inclusion of 44 ears of tinnitus patients and 57 ears of control subjects. INTERVENTION: Suppression of the otoacoustic emissions generated by the 65-dB click stimulus was tested using contralateral broadband noise at 70 dB SPL. Suppression was calculated in half-octave frequency bands centered at 1.0, 1.4, 2.0, 2.8, and 4.0 kHz. MAIN OUTCOME MEASURE: The amount of suppression of the OAE, calculated in half-octave frequency bands. RESULTS: Otoacoustic emission amplitudes were equal in both groups. Contralateral suppression of the signal was found in both patients and controls. The amount of suppression was equal, except for the 2.0- and 2.8-kHz frequency bands in the right ear (p value of 0.03, 0.008, respectively), for which the patients had less suppression. CONCLUSION: The suppression of otoacoustic emissions with CAS seems equally effective in tinnitus patients and healthy controls. The minor differences between both groups suggest subtle differences in the function of the medial olivocochlear efferent system.
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The more the worse: the grade of noise-induced hearing loss associates with the severity of tinnitus. Int J Environ Res Public Health. 2010 Aug;7(8):3071-9. Epub 2010 Aug 4. Mazurek B, Olze H, Haupt H, Szczepek AJ. Dept of Otorhinolaryngology CCM, Charité-Universitätsmedizin Berlin, Germany. [email protected]
Tinnitus disturbs lives and negatively affects the quality of life of about 2% of the adult world population. Research has shown that the main cause of tinnitus is hearing loss. To analyze a possible association of the degree of hearing loss with the severity of tinnitus, we have performed a retrospective study using admission data on 531 patients suffering from chronic tinnitus. We have found that 83% of our tinnitus patients had a high frequency hearing loss corresponding to a noise-induced hearing loss (NIHL). There was a significant correlation between the mean hearing loss and the tinnitus loudness (p < 0.0001). Interestingly, patients suffering from decompensated chronic tinnitus had a greater degree of hearing loss than the patients with compensated form of tinnitus. In addition, we demonstrate that the degree of hearing loss positively correlates with the two subscales (“intrusiveness” and “auditory perceptional difficulties”) of the Tinnitus Questionnaire. Our retrospective study provides indirect evidence supporting the hypothesis that the degree of noise-induced hearing loss influences the severity of tinnitus. Familiar Meniere‘s disease restricted to 1.48 Mb on chromosome 12p12.3 by allelic and haplotype association. J Hum Genet. 2010 Dec;55(12):834-7. Epub 2010 Oct 7. Gabriková D, Frykholm C, Friberg U, Lahsaee S, Entesarian M, Dahl N, Klar J. Dept of Genetics and Pathology, The Rudbeck Laboratory, Uppsala University, Sweden, Dept of Biology, Faculty of Humanities and Natural Sciences, University of Prešov, Slovakia. Meniere‘s disease (MD) is a disorder of the inner ear characterized by episodes of vertigo, tinnitus and fluctuating sensorineural hearing loss. Most MD cases are sporadic, but 5-15% of patients are familial following an autosomal dominant mode of inheritance with incomplete penetrance. We have previously identified a candidate gene region for MD on chromosome 12p12.3 using linkage analysis. We genotyped 15 Swedish families segregating familial MD (FMD) to further clarify the role of chromosome 12p in a larger cohort of families. Highly polymorphic marker loci were analyzed over the 16-Mb candidate region in affected and healthy family members as well as in control subjects. The results revealed allelic association between FMD and several individual polymorphic marker alleles and single-nucleotide polymorphisms. Moreover, a common three-marker haplotype spanning 1.48 Mb co-segregates with FMD in 60% of the families investigated, forming the core of a possible ancestral haplotype associated with FMD in Sweden. Expression and translocation of aquaporin-2 in the endolymphatic sac in patients with Meniere‘s disease. J Neuroendocrinol. 2010 Nov;22(11):1157-64. doi: 10.1111/j.1365-2826.2010.02060.x. Maekawa C, Kitahara T, Kizawa K, Okazaki S, Kamakura T, Horii A, Imai T, Doi K, Inohara H, Kiyama H. Dept of Otolaryngology, Osaka University, School of Medicine, Suita-city, Osaka, Japan. Meniere‘s disease, characterised by episodic vertigo, fluctuating hearing loss and tinnitus, can occur under conditions of stress. Its pathology was first revealed to be inner ear hydrops through temporal bone studies in 1938. Although its pathogenesis has been proposed to be a disorder of water transport in the inner ear, subsequently, it remains unsolved, until now. A recent study revealed that both plasma stress hormone, vasopressin (pAVP) and its receptor, V2 (V2R) expression in the inner ear endolymphatic sac were significantly higher in Meniere‘s patients. In the present study, to link V2R-III back to content
related molecules and inner ear hydrops, we examined V2R-linked water channel molecule, aquaporin-2 (AQP2) expression and translocation in human endolymphatic sac. AQP2 mRNA expression in the endolymphatic sac was significantly higher in Meniere‘s patients by using real-time polymerase chain reaction, as further confirmed by western blotting. AQP2-like immunoreactivity (-LIR) was translocated from luminal to basolateral side with endosomal trapping in the endolymphatic sac at the time of AVP exposure in human endolymphatic sac tissue culture. The similar AQP2-LIR translocation was also demonstrated by forskolin and blocked by vasopressin/V2R specific antagonist, OPC31260 and protein kinase A (PKA) specific antagonists, H-89 and KT-5720. We concluded that in the pathogenesis of inner ear hydrops resulting in Meniere‘s attacks, pAVP elevation as a result of stress and subsequent V2R-cAMP-PKA-AQP2 activation and endosomal trapping of AQP2 in the endolymphatic sac, might be important as a basis of this disease. Further experimental and clinical studies are needed to better clarify the neuroscientific relationship between stress and Meniere‘s disease. Expression of COX-2 and NMDA receptor genes at the cochlea and midbrain in salicylate-induced tinnitus. Laryngoscope. 2011 Feb;121(2):361-364. doi: 10.1002/lary.21283. Epub 2011 Jan 13. Hwang JH, Chen JC, Yang SY, Wang MF, Liu TC, Chan YC. Depts of Otolaryngology, Buddhist Dalin Tzu-Chi General Hospital, Chiayi, Taiwan; School of Medicine, Tzu Chi University, Hualien, Taiwan; Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan. OBJECTIVE/HYPOTHESIS: The expression of the genes for cyclooxygenase (COX) and NMDA receptor (NR) has seldom been reported in tinnitus. We hypothesized that expression of COX-2 and NR was altered in the cochlea and midbrain in salicylate-induced tinnitus. STUDY DESIGN: Experimental study on mice. METHODS: We evaluated the tinnitus score and mRNA expression levels of COX-2 and NR subtype 2B (NR2B) in the cochlea and midbrain in response to intraperitoneal injections of salicylate for 4 days. RESULTS: At day 4 of tinnitus induction, the mean weights of the whole body and midbrain did not change greatly in both control and salicylate groups. The tinnitus score was not elevated from day 1 to day 4 in the control group, but increased day by day in the salicylate group. The mRNA expression level of COX-2 decreased slightly in the salicylate group in the cochlea (1.1 ± 0.33 vs. 1.3 ± 0.49, P = .0752) and in the midbrain (0.9 ± 0.10 versus 1.0 ± 0.35, P = .0489). Inversely, the expression levels of the NR2B gene increased moderately in the salicylate group in the cochlea (3.7 ± 0.47 versus 2.3 ± 1.13, P < 0.0001) and in the midbrain (1.6 ± 0.64 versus 1.0 ± 0.44, P = .0007). CONCLUSIONS: Salicylate induced tinnitus and altered the expression of the COX-2 and NR2B genes in the cochlea and midbrain of mice. These findings might contribute to further understanding of pathophysiology and therapy of tinnitus. Laryngoscope, 2011. Copyright © 2010 The American Laryngological, Rhinological, and Otological Society, Inc. Theta-gamma dysrhythmia and auditory phantom perception. J Neurosurg. 2011 Jan 14. [Epub ahead of print] De Ridder D, van der Loo E, Vanneste S, Gais S, Plazier M, Kovacs S, Sunaert S, Menovsky T, van de Heyning P. Tinnitus is considered an auditory phantom percept analogous to phantom pain. Thalamocortical dysrhythmia has been proposed as a possible pathophysiological mechanism for both tinnitus and pain. Thalamocortical dysrhythmia refers to a persistent pathological resting state theta-gamma coupling that is spatially localized at an area where normally alpha oscillations predominate. Auditory cortex stimulation via implanted electrodes has been developed to treat tinnitus, targeting an area of activation on functional MR imaging elicited by tinnitus-matched sound presentation. The authors describe a case in which clinical improvement was correlated with changes in intracranial recordings. Maximal tinnitus suppression was obtained by current delivery exactly at the blood oxygen level-dependent back to content
activation hotspot, which colocalizes with increased gamma and theta activity, in contrast to the other electrode poles, which demonstrated a normal alpha peak. These spectral changes normalized when stimulation induced tinnitus suppression, both on electrode and source-localized electroencephalography recordings. These data suggest that thetagamma coupling as proposed by the thalamocortical dysrhythmia model might be causally related to a conscious auditory phantom percept. Dysregulation of limbic and auditory networks in tinnitus. Neuron. 2011 Jan 13;69(1):33-43. Leaver AM, Renier L, Chevillet MA, Morgan S, Kim HJ, Rauschecker JP. Laboratory of Integrative Neuroscience and Cognition, Georgetown University Medical Center, Washington, DC 20057, USA. Tinnitus is a common disorder characterized by ringing in the ear in the absence of sound. Converging evidence suggests that tinnitus pathophysiology involves damage to peripheral and/or central auditory pathways. However, whether auditory system dysfunction is sufficient to explain chronic tinnitus is unclear, especially in light of evidence implicating other networks, including the limbic system. Using functional magnetic resonance imaging and voxel-based morphometry, we assessed tinnitus-related functional and anatomical anomalies in auditory and limbic networks. Moderate hyperactivity was present in the primary and posterior auditory cortices of tinnitus patients. However, the nucleus accumbens exhibited the greatest degree of hyperactivity, specifically to sounds frequency-matched to patients‘ tinnitus. Complementary structural differences were identified in ventromedial prefrontal cortex, another limbic structure heavily connected to the nucleus accumbens. Furthermore, tinnitus-related anomalies were intercorrelated in the two limbic regions and between limbic and primary auditory areas, indicating the importance of auditory-limbic interactions in tinnitus. Copyright © 2011 Elsevier Inc. All rights reserved. back to Highlights Rapid increases of gamma power in the auditory cortex following noise trauma in humans. Eur J Neurosci. 2010 Dec 29. doi: 10.1111/j.1460-9568.2010.07542.x. [Epub ahead of print] Ortmann M, Müller N, Schlee W, Weisz N. Institute for Biomagnetism and Biosignalanalysis, University of Münster, Germany, Depart of Psychology, University of Konstanz, Konstanz, Germany Zukunftskolleg, University of Konstanz, Germany. Tinnitus is an auditory perception in the absence of any external sound source. It has been suggested that tinnitus is related to enhanced synchronization of neuronal activity in the auditory cortex. Usually a hearing damage can be identified suggesting auditory deprivation to central auditory regions to be fundamental for neurophysiological processes related to tinnitus. Until now, human research has been conducted on patients with chronic tinnitus (> 6 months). However, neuronal activity accompanying auditory deprivation and putatively tinnitus may not remain constant over time, making it difficult to directly relate outcomes of current animal studies (acute tinnitus) to chronic tinnitus in humans, and vice versa. We investigated 14 amateur rock musicians who frequently reported a short-term tinnitus immediately after band practice. Magnetoencephalographic resting-state recordings, audiometry and tinnitus testing were performed at two separate occasions: with and without previous exposure to loud music. Analyses revealed that transient tinnitus was accompanied by temporary hearing loss in both ears and increased gamma activity in the right auditory cortex in 13 out of 14 cases. Additionally, tinnitus frequency was strongly correlated to hearing loss. Analogous to animal studies, our results show for the first time in humans that noise trauma leads rapidly to increased neuronal synchrony in the auditory cortex. Importantly, the strongly right-lateralized effect implies that it does not reflect tinnitus percept per se. This could rather have been triggered by greater discontinuities of hearing loss at high frequencies that were particularly pronounced in the left ear. © 2010 The Authors. European Journal of Neuroscience © 2010 Federation of European Neuroscience Societies and Blackwell Publishing Ltd. back to Highlights back to content
Cholinergic cells of the pontomesencephalic tegmentum: Connections with auditory structures from cochlear nucleus to cortex. Hear Res. 2010 Dec 30. [Epub ahead of print] Schofield BR, Motts SD, Mellott JG. Department of Anatomy and Neurobiology, Northeastern Ohio Universities College of Medicine, PO Box 95, Rootstown, OH 44272, USA; School of Biomedical Sciences, Kent State University, Kent, OH, USA. Acetylcholine (ACh) is a neuromodulator that is likely to play a role in plasticity as well as other phenomena at many sites in the auditory system. The auditory cortex receives cholinergic innervation from the basal forebrain, whereas the cochlea receives cholinergic innervation from the superior olivary complex. Much of the remainder of the auditory pathways receives innervation from the pedunculopontine and laterodorsal tegmental nuclei, two nuclei referred to collectively as the pontomesencephalic tegmentum (PMT). The PMT provides the major source of ACh to the auditory thalamus and the midbrain, and is a substantial source (in addition to the superior olivary complex) of ACh in the cochlear nucleus. Individual cholinergic cells in the PMT often have axon branches that innervate multiple auditory nuclei, including nuclei on both sides of the brain as well as nuclei at multiple levels of the auditory system. The auditory cortex has direct axonal projections to the PMT cells, including cholinergic cells that project to the inferior colliculus or cochlear nucleus. The divergent projections of PMT cholinergic cells suggest widespread effects on the auditory pathways. These effects are likely to include plasticity as well as novelty detection, sensory gating, reward behavior, arousal and attention. Descending projections from the forebrain, including the auditory cortex, are likely to provide a high level of cognitive input to these cholinergic effects. Dysfunction associated with the cholinergic system may play a role in disorders such as tinnitus and schizophrenia. Copyright © 2011 Elsevier B.V. All rights reserved.
III Diagnostics [GIN Test (Gaps-in-Noise) in normal listeners with and without tinnitus]. Pro Fono. 2010 Sep;22(3):257-62. Sanches SG, Samelli AG, Nishiyama AK, Sanchez TG, Carvallo RM. Fonoaudióloga, Faculdade de Medicina, Universidade de São Paulo, Brazil. [email protected]
BACKGROUND: the Gaps-in-Noise (GIN) test assesses the auditory temporal resolution skill. Studies have described the GIN test an instrument of easy application and with good sensitivity and specificity. AIM: to compare the results of the GIN test in normal listeners with and without tinnitus and to correlate the obtained results with pure tone thresholds and age. METHOD: hearing tests were performed in 44 subjects (hearing threshold up to 25 dB HL in the frequencies of 0.25 to 8 kHz). Two groups were considered for comparison: the Control Group with 23 subjects, 8 men and 15 women, aged between 2240 (mean 29.7), and the Research Group with 18 tinnitus patients, 3 men and 15 women, aged between 21-45 (mean 31.3). All subjects underwent pure tone audiometry, speech tests, acoustic immittance measurements and the GIN test. For the statistical analysis, the significance level of 0.05 was adopted. RESULTS: considering pure tone audiometry, the overall mean for hearing thresholds was significantly higher for the Research Group when compared to the Control Group (p = 0.001). The comparison between the groups for the performance in the GIN test indicated that the Control Group detected gaps with a shorter time interval than the Research Group (p < 0.001). There was no correlation between the age of the subjects and the level of the GIN test. CONCLUSION: the GIN test identified deficit in the hearing skill of temporal resolution in patients with tinnitus. In the studied age group (21 to 45 years) there was no correlation between age and the results obtained in the GIN test.
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[Temporal resolution and selective attention of individuals with tinnitus]. [Article in Portuguese] Pro Fono. 2010 Sep;22(3):233-8. Acrani IO, Pereira LD. Departamento de Fonoaudiologia, Universidade Federal de São Paulo. BACKGROUND: speech comprehension difficulty is a very common complaint of individuals with tinnitus with and without hearing loss. This study was conducted in order to analyze if tinnitus interferes in auditory processing and speech comprehension in individuals with normal hearing levels. AIM: to asses and compare the auditory behavior of temporal resolution and selective attention of adults with normal hearing levels with and without tinnitus. METHOD: 45 individuals, 15 with continuous tinnitus and 30 without tinnitus were selected and assessed by three auditory processing tests: Speech in Noise Test, Dichotic Digits Test and Gaps in Noise. After that, the results of each group were compared by appropriated statistic‘s tests; one of them was ANOVA. RESULTS: there were no significant statistical differences between the groups and both ears. CONCLUSION: tinnitus did not interfere in the auditory abilities of selective attention and temporal resolution. Use of optical coherence tomography to evaluate papilledema and pseudopapilledema. Semin Ophthalmol. 2010 Sep-Nov;25(5-6):198-205. Heidary G, Rizzo JF 3rd. Neuro-Ophthalmology Service, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA. [email protected]
Idiopathic intracranial hypertension (IIH), or pseudotumor cerebri, describes a condition of elevated intracranial pressure (ICP) that typically presents in obese women of childbearing age with symptoms and signs of posture-dependent headaches, pulsatile tinnitus, visual changes, and papilledema. Optical coherence tomography (OCT) has begun to be utilized as an adjunctive, quantitative tool in the evaluation of patients with IIH to help distinguish between true optic nerve head edema and pseudopapilledema, and to contribute to our understanding of the consequences of prolonged optic nerve edema. Although few longitudinal studies of patients with IIH have been published to date, it appears that there may be a correlation between retinal nerve fiber layer (RNFL) thickness and visual function. With the new spectral domain OCT, additional parameters of the optic nerve imaging, including volume and height measurements, might provide greater sensitivity of the response to treatment and the long-term visual outcome in patients with IIH. [Different prognostic characteristics between profound sudden sensorineural hearing loss and total sudden hearing loss]. [Article in Chinese] Zhonghua Er Bi Yan Hou Tou Jing Wai Ke Za Zhi. 2010 Jul;45(7):570-3. Zhao H, Fu YY, Zhang TY, Chi FL, Jing JH. Department of Otorhinolaryngology, Eye Ear Nose and Throat Hospital, Fudan University, Shanghai 200031, China. OBJECTIVE: To clarify the different prognostic characteristics between profound sudden sensorineural hearing loss (SSNHL) and total SSNHL. METHODS: The patients with SSNHL who visited Eye Ear Nose and Throat Hospital from June 2007 to September 2008 were reviewed retrospectively. All the 204 patients, with pure tone average (PTA) threshold more than 90 dB, were enrolled and divided into two groups, including total SSNHL and profound SSNHL groups. The relationship between recovery rate and prognostic factors including the age, complications, time period between onset and therapy was analyzed. back to content
RESULTS: There were 57 cases of total SSNHL and 147 cases of profound SSNHL in this series. Tinnitus was complained in more than 90% of the patients in both groups, which was higher than that of dizziness and ear fullness. Dizziness was present in 64.9% (37/57) patient with total SSNHL group and 45.6% (67/147) patients with profound SSNHL, which had significant difference between the two groups (χ(2) = 5.72, P = 0.017). The PTA threshold improvement in total SSNHL group and profound SSNHL group was (36.4 ± 19.3) dB and (40.2 ± 21.3) dB respectively, which was no significant difference between the two groups (t = 1.165, P = 0.245). The cured patients were all those received therapy within 1 week following the onset of SSNHL, which was of 2.6% (1/38) patients in the total SSNHL group and 14.3% (14/98) patients in the profound SSNHL group (P = 0.045). Furthermore, 3.5% (2/57) patients in total SSNHL group as well as 29.9% (44/147) patients in profound SSNHL group obtained a good result with PTA threshold ≤ 50 dB after therapy (χ(2) = 15.92, P = 0.001). In addition, the favorable prognosis was related with the onset-therapy time point(P = 0.001), but not related to the patients’ age. CONCLUSION: Profound SSNHL and total SSNHL though both with PTA threshold > 90 dB had significant differences recovery rate and need to be studied separately Clinical characteristics and audiological significance of spontaneous otoacoustic emissions in tinnitus patients with normal hearing. J Laryngol Otol. 2010 Nov 5:1-5. [Epub ahead of print] Kim DK, Park SN, Park KH, Choi HG, Jeon EJ, Park YS, Yeo SW. Department of Otolaryngology-Head and Neck Surgery, The Catholic University of Korea, College of Medicine, Seoul, South Korea. Objective:To define the clinical and audiological features of normal-hearing tinnitus patients with spontaneous otoacoustic emissions, and to evaluate the role of spontaneous otoacoustic emissions in tinnitus generation.Materials and methods:Thirty-two patients with spontaneous otoacoustic emissions were compared with 29 patients without spontaneous otoacoustic emissions, regarding clinical and audiological aspects.Results:The mean age of the study group subjects was significantly lower, and they experienced the kindling effect less frequently than the control group. The mean tinnitus handicap inventory score of the study group was considerably higher than that of the controls, although the difference was not statistically significant. The study group had significantly quieter tinnitus, and higher transient evoked and distortion product otoacoustic emission responses, compared with the control group.Conclusions:Normal-hearing tinnitus patients with spontaneous otoacoustic emissions have different clinical and audiological characteristics, compared with those without spontaneous otoacoustic emissions. Appropriate evaluation and treatment should be considered at an early stage in these patients. Contralateral Suppression of Otoacoustic Emissions in Tinnitus Patients. Otol Neurotol. 2010 Oct 19. [Epub ahead of print] Geven LI, de Kleine E, Free RH, van Dijk P. Department of Otorhinolaryngology-Head and Neck Surgery, and †Faculty of Medical Sciences, School of Behavioral and Cognitive Neurosciences, University of Groningen, Groningen, The Netherlands. OBJECTIVE: To compare the functioning of the medial olivocochlear efferent system between tinnitus patients and control subjects. STUDY DESIGN: Prospective, nonrandomized controlled analysis of suppression of otoacoustic emissions with contralateral acoustic stimulation. SETTING: Tertiary referral center. PATIENTS: Initial analysis of 97 tinnitus patients and 44 control subjects with click-evoked otoacoustic emission measurement. If subjects had reproducible otoacoustic emissions at 80 dB SPL, suppression of otoacoustic emission with contralateral acoustic stimulation was measured with a 65-dB click stimulus. This resulted in inclusion of 44 ears of tinnitus patients and 57 ears of control subjects.
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INTERVENTION: Suppression of the otoacoustic emissions generated by the 65-dB click stimulus was tested using contralateral broadband noise at 70 dB SPL. Suppression was calculated in half-octave frequency bands centered at 1.0, 1.4, 2.0, 2.8, and 4.0 kHz. MAIN OUTCOME MEASURE: The amount of suppression of the OAE, calculated in half-octave frequency bands. RESULTS: Otoacoustic emission amplitudes were equal in both groups. Contralateral suppression of the signal was found in both patients and controls. The amount of suppression was equal, except for the 2.0- and 2.8-kHz frequency bands in the right ear (p value of 0.03, 0.008, respectively), for which the patients had less suppression. CONCLUSION: The suppression of otoacoustic emissions with CAS seems equally effective in tinnitus patients and healthy controls. The minor differences between both groups suggest subtle differences in the function of the medial olivocochlear efferent system Accuracy of 3.0 Tesla magnetic resonance imaging in the diagnosis of intracochlear schwannoma. Auris Nasus Larynx. 2011 Jan 18. [Epub ahead of print] Yoshida T, Sone M, Naganawa S, Nakashima T. Department of Otorhinolaryngology, Nagoya University Graduate School of Medicine, Nagoya, Japan. Intracochlear schwannomas (ICSs) are rare tumors. The diagnosis of ICS is based on high-resolution magnetic resonance imaging (MRI), which should be used for the accurate determination of the location of tumors. Recent advancements in imaging technologies and software enable the precise regional diagnosis of ICS. We experienced a case of intracochlear schwannoma with a diagnosis of progressive hearing loss and tinnitus. Audiometry revealed severe hearing loss in the right ear with remaining lowfrequency hearing. MRI showed an abnormal lesion in the cochlea. Three-dimensional real inversion recovery (3D rIR) and constructive interference in steady state (CISS) MRI revealed the size and shape of the tumor via identification of the cochlear nerve and cochlear fluid space. CISS and 3D rIR sequences provide useful information regarding the boundaries of tumors and the tissues that surround them.
IV Imaging Evidence of key tinnitus-related brain regions documented by a unique combination of manganese-enhanced MRI and acoustic startle reflex testing. PLoS One. 2010 Dec 15;5(12):e14260. Holt AG, Bissig D, Mirza N, Rajah G, Berkowitz B. Dept of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA. Animal models continue to improve our understanding of tinnitus pathogenesis and aid in development of new treatments. However, there are no diagnostic biomarkers for tinnitus-related pathophysiology for use in awake, freely moving animals. To address this disparity, two complementary methods were combined to examine reliable tinnitus models (rats repeatedly administered salicylate or exposed to a single noise event): inhibition of acoustic startle and manganese-enhanced MRI. Salicylate-induced tinnitus resulted in wide spread supernormal manganese uptake compared to noise-induced tinnitus. Neither model demonstrated significant differences in the auditory cortex. Only in the dorsal cortex of the inferior colliculus (DCIC) did both models exhibit supernormal uptake. Therefore, abnormal membrane depolarization in the DCIC appears to be important in tinnitus-mediated activity. Our results provide the foundation for future studies correlating the severity and longevity of tinnitus with hearing loss and neuronal activity in specific brain regions and tools for evaluating treatment efficacy across paradigms.
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The differences in brain activity between narrow band noise and pure tone tinnitus. PLoS One. 2010 Oct 27;5(10):e13618. Vanneste S, Plazier M, van der Loo E, Van de Heyning P, De Ridder D. Department of Neurosurgery, University Hospital Antwerp, Brai2n, Tinnitus Research Institute, Edegem, Belgium. [email protected]
BACKGROUND: Tinnitus is an auditory sensation characterized by the perception of sound or noise in the absence of any external sound source. Based on neurobiological research, it is generally accepted that most forms of tinnitus are attributable to maladaptive plasticity due to damage to auditory system. Changes have been observed in auditory structures such as the inferior colliculus, the thalamus and the auditory cortex as well as in non-auditory brain areas. However, the observed changes show great variability, hence lacking a conclusive picture. One of the reasons might be the selection of inhomogeneous groups in data analysis. METHODOLOGY: The aim of the present study was to delineate the differences between the neural networks involved in narrow band noise and pure tone tinnitus conducting LORETA based source analysis of resting state EEG. CONCLUSIONS: Results demonstrated that narrow band noise tinnitus patients differ from pure tone tinnitus patients in the lateral frontopolar (BA 10), PCC and the parahippocampal area for delta, beta and gamma frequency bands, respectively. The parahippocampal-PCC current density differences might be load dependent, as noiselike tinnitus constitutes multiple frequencies in contrast to pure tone tinnitus. The lateral frontopolar differences might be related to pitch specific memory retrieval. Neuroanatomical changes due to hearing loss and chronic tinnitus: A combined VBM and DTI study. Brain Res. 2011 Jan 19;1369:74-88. Epub 2010 Nov 1. Husain FT, Medina RE, Davis CW, Szymko-Bennett Y, Simonyan K, Pajor NM, Horwitz B. Department of Speech and Hearing Science, University of Illinois at Urbana-Champaign, Champaign, IL, USA; Brain Imaging and Modeling Section, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA. Subjective tinnitus is the perception of sound in the absence of an external source. Tinnitus is often accompanied by hearing loss but not everyone with hearing loss experiences tinnitus. We examined neuroanatomical alterations associated with hearing loss and tinnitus in three groups of subjects: those with hearing loss with tinnitus, those with hearing loss without tinnitus and normal hearing controls without tinnitus. To examine changes in gray matter we used structural MRI scans and voxel-based morphometry (VBM) and to identify changes in white matter tract orientation we used diffusion tensor imaging (DTI). A major finding of our study was that there were both gray and white matter changes in the vicinity of the auditory cortex for subjects with hearing loss alone relative to those with tinnitus and those with normal hearing. We did not find significant changes in gray or white matter in subjects with tinnitus and hearing loss compared to normal hearing controls. VBM analysis revealed that individuals with hearing loss without tinnitus had gray matter decreases in anterior cingulate and superior and medial frontal gyri relative to those with hearing loss and tinnitus. Region-of-interest analysis revealed additional decreases in superior temporal gyrus for the hearing loss group compared to the tinnitus group. Investigating effects of hearing loss alone, we found gray matter decreases in superior and medial frontal gyri in participants with hearing loss compared to normal hearing controls. DTI analysis showed decreases in fractional anisotropy values in the right superior and inferior longitudinal fasciculi, corticospinal tract, inferior fronto-occipital tract, superior occipital fasciculus, and anterior thalamic radiation for the hearing loss group relative to normal hearing controls. In attempting to dissociate the effect of tinnitus from hearing loss, we observed that hearing loss rather than tinnitus had the greatest influence on gray and white matter alterations.
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A diffusion tensor imaging study on the auditory system and tinnitus. Open Neuroimag J. 2010 Jun 30;4:16-25. Crippa A, Lanting CP, van Dijk P, Roerdink JB. Johann Bernoulli Institute for Mathematics and Computer Science, University of Groningen, The Netherlands. Tinnitus is an auditory percept in the absence of an external sound source. Mechanisms in the central nervous system are believed to be key in the pathophysiology of tinnitus. Diffusion tensor imaging (DTI) is an MR imaging technique that allows in vivo exploration of white matter tissue in the human brain. Using a probabilistic DTI approach, we determined the characteristics of fiber tracts from the inferior colliculus to the medial geniculate body up to the primary auditory cortex. We also investigated the connections between the auditory system and the amygdala, which may be involved in some forms of tinnitus. White matter tracts were characterized by three quantities: the mean fractional anisotropy, the weighted mean fractional anisotropy and the path strength. All these quantities are measures of the patency of white matter tracts. The most important finding is an increased patency of the white matter tracts between the auditory cortex and the amygdala in tinnitus patients as compared to healthy controls Tinnitus, diminished sound-level tolerance, and elevated auditory activity in humans with clinically normal hearing sensitivity. J Neurophysiol. 2010 Dec;104(6):3361-70. Epub 2010 Sep 29. Gu JW, Halpin CF, Nam EC, Levine RA, Melcher JR. Eaton-Peabody Lab., Massachusetts Eye and Ear Infirmary, 243 Charles St., Boston, MA 02114, USA. [email protected]
Phantom sensations and sensory hypersensitivity are disordered perceptions that characterize a variety of intractable conditions involving the somatosensory, visual, and auditory modalities. We report physiological correlates of two perceptual abnormalities in the auditory domain: tinnitus, the phantom perception of sound, and hyperacusis, a decreased tolerance of sound based on loudness. Here, subjects with and without tinnitus, all with clinically normal hearing thresholds, underwent 1) behavioral testing to assess sound-level tolerance and 2) functional MRI to measure sound-evoked activation of central auditory centers. Despite receiving identical sound stimulation levels, subjects with diminished sound-level tolerance (i.e., hyperacusis) showed elevated activation in the auditory midbrain, thalamus, and primary auditory cortex compared with subjects with normal tolerance. Primary auditory cortex, but not subcortical centers, showed elevated activation specifically related to tinnitus. The results directly link hyperacusis and tinnitus to hyperactivity within the central auditory system. We hypothesize that the tinnitus-related elevations in cortical activation may reflect undue attention drawn to the auditory domain, an interpretation consistent with the lack of tinnitus-related effects subcortically where activation is less potently modulated by attentional state. The data strengthen, at a mechanistic level, analogies drawn previously between tinnitus/hyperacusis and other, nonauditory disordered perceptions thought to arise from neural hyperactivity such as chronic neuropathic pain and photophobia. back to Highlights
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Dysregulation of limbic and auditory networks in tinnitus. Neuron. 2011 Jan 13;69(1):33-43. Leaver AM, Renier L, Chevillet MA, Morgan S, Kim HJ, Rauschecker JP. Laboratory of Integrative Neuroscience and Cognition, Georgetown University Medical Center, Washington, DC 20057, USA. Tinnitus is a common disorder characterized by ringing in the ear in the absence of sound. Converging evidence suggests that tinnitus pathophysiology involves damage to peripheral and/or central auditory pathways. However, whether auditory system dysfunction is sufficient to explain chronic tinnitus is unclear, especially in light of evidence implicating other networks, including the limbic system. Using functional magnetic resonance imaging and voxel-based morphometry, we assessed tinnitus-related functional and anatomical anomalies in auditory and limbic networks. Moderate hyperactivity was present in the primary and posterior auditory cortices of tinnitus patients. However, the nucleus accumbens exhibited the greatest degree of hyperactivity, specifically to sounds frequency-matched to patients’ tinnitus. Complementary structural differences were identified in ventromedial prefrontal cortex, another limbic structure heavily connected to the nucleus accumbens. Furthermore, tinnitus-related anomalies were intercorrelated in the two limbic regions and between limbic and primary auditory areas, indicating the importance of auditory-limbic interactions in tinnitus. Copyright © 2011 Elsevier Inc. All rights reserved.
V Pharmacotherapy [Vinpotropil in the treatment of dyscirculatory encephalopathy with cognitive impairment without dementia.] [Article in Russian] Zh Nevrol Psikhiatr Im S S Korsakova. 2010;110(11):13-16. Zakharov VV. Kafedra nervnykh bolezneĭ Pervogo MGMU im. I.M. Sechenova. The fixed combination containing 5 mg of vinpocetine and 400 mg of pyracetam (vinpotropil) was prescribed to 349 patients with dyscirculatory encephalopathy, I-II stages in dose one capsule three times a day during 3 months. After this treatment, repeated neuropsychological testing showed significant diminishing of dysexecutive cognitive impairment linked with frontal lobes dysfunction. The cognitive improvement was associated with the regress of subjective neurological symptoms like headache, dizziness, tinnitus, fatigue and insomnia. Vinpotropil was safe and well tolerated in elderly patients with chronic cerebral vascular insufficiency. Endoscopic intratympanic methylprednisolone injection for treatment of refractory sudden sensorineural hearing loss and one case in pregnancy. J Otolaryngol Head Neck Surg. 2010 Dec;39(6):640-5. Chen Y, Wen L, Hu P, Qiu J, Lu L, Qiao L. Department of Otolaryngology-Head and Neck Surgery, Xijing Hospital, Fourth Military Medical University, Xi‘an, China. [email protected]
OBJECTIVE: to evaluate the effectiveness of transtympanic methylprednisolone injection in patients with refractory sudden sensorineural hearing loss via endoscopic diode laser myringotomy. SUBJECTS AND METHODS: thirty-six sudden sensorineural hearing loss patients who failed routine oral steroid therapy and two patients with a contraindication to systemic steroid received intratympanic methylprednisolone injections at the round window by endoscopic diode laser myringotomy once every other day with a back to content
maximum of four injections. One of the two patients with a contraindication to oral steroid was a normal pregnant woman, whereas the other was an active digestive ulcer patient. Hearing level, dizziness, and tinnitus were evaluated before the first procedure and 20 days after the last injection. RESULTS: thirteen of 38 patients (34.2%) showed an improvement in hearing levels. The average improvement 20 days after treatment was 54 dB in the hearing thresholds of 125 to 8000 Hz. The complete recovery rate of intratympanic methylprednisolone injection (mean 2.6 times) was 21% (8 of 38). There were no serious unexpected adverse events in the 38 patients except one aggravation of hearing loss occurred after intratympanic injection. Temporary dizziness in seven subjects and otalgia in six subjects occurred after injection, which was relieved after 0.5 to 2 hours without special treatment. No perforation of tympanic membrane or infection occurred 20 days after the last injection. CONCLUSIONS: topical intratympanic injection may be considered a substitute for the systemic administration in patients with refractory sudden hearing loss, especially those who have contraindications to systemic steroid administration. The endoscope is helpful for ensuring the effective delivery of drugs into the round window. Prospective randomized controlled trials should be designed for further investigation. Improvement in cochlear flow with Pycnogenol® in patients with tinnitus: a pilot evaluation. Panminerva Med. 2010 Jun;52(2 Suppl 1):63-7. Grossi MG, Belcaro G, Cesarone MR, Dugall M, Hosoi M, Cacchio M, Ippolito E, Bavera P. Irvine3 Labs, Department of Biomedical Sciences, Chieti-Pescara University, Pescara, Italy. AIM: The aim of this preliminary evaluation was to study the efficacy of Pycnogenol in improving cochlear flow in patients with mild-to-moderate tinnitus present for at least two weeks (without vertigo or important hearing loss), possibly associated with cochlear hypo-perfusion. METHODS: Patients with mild-to-moderate, idiopatic, monolateral tinnitus present for at least 2 weeks were included; no vertigo or important hearing loss had been found in a specific examination. The origin of tinnitus had been sudden (hours or days). Fifty-eight patients used Pycnogenol: 24 used 150 mg/day (group A; mean age 43.2+/4.3) and 34 patients 100 mg/day (group B: mean age 42.4+/-3.8). Controls included 24 patients (mean age 42.3+/-4.5). The groups were comparable for their clinical problem and age and sex. The average duration of treatment was 34.3+/-3.1 days. No side effects were observed and no drop-outs occurred. RESULTS: The variations in cochlear flow velocity (in cm/s at the cochlear artery), at inclusion and after four weeks of treatment indicated that flow velocity at the level of the affected ear was significantly lower (both the diastolic and systolic components; P